Electronic MEMS for triggered delivery

Implantable electronic devices such as pacemakers and neural implants are often used for electrical stimulation. The usage of microfabrication techniques to produce microelectromechanical systems (MEMS) has allowed engineers to address a wider range of clinical indications. A new direction in the area of MEMS technology is the goal of achieving pulsatile drug delivery. The digital capabilities of MEMS may allow greater temporal control over drug release compared to traditional polymer-based systems, while the batch-processing techniques used in the microelectronics industry can lead to greater device uniformity and reproducibility than is currently available to the pharmaceutical industry. A repertoire of structures, including microreservoirs, micropumps, valves, and sensors, is being developed that will provide a strong foundation for the design of integrated, responsive MEMS for drug delivery.     

Chemically synthesized protein as tumour-specific vaccine: immunogenicity and efficacy of synthetic HPV16 E7 in the TC-1 mouse tumour model

Many successful candidate vaccines capable of combating tumours in animal models come to an untimely end because of the costs associated with the approval and production of the GMP-grade materials, which are usually of biological origin, for use in humans. We have used a GMP-compatible method to chemically synthesize a pure synthetic E7 protein of the human papillomavirus type 16 (HPV16-E7). This oncogen-derived protein is constitutively expressed in cervical cancer and its precursors and is thus considered as an excellent target for tumour-specific immunity. Injection of a mixture of the synthetic HPV16-E7 protein and the synthetic adjuvant CpG in mice resulted in strong functional HPV16-specific cytotoxic T-lymphocyte responses as measured by CD8+ MHC class I-tetramer staining, the detection of antigen-specific intracellular IFNgamma production and the ability to protect mice against a challenge with HPV16-E7+ TC-1 tumour cells in both prophylactic and therapeutic vaccination regimens. Our results demonstrate the potential use of pure synthetic vaccines that can be efficiently produced under GMP at low cost, which will stimulate the translation of new vaccination strategies into phase I/II clinical trials.     

Molding of the regenerate in mandibular distraction: Part 1: Laboratory study

Distraction osteogenesis has evolved as a mainstream surgical technique for lengthening and augmentation of the hypoplastic mandible. As clinical experience accumulated, there developed the need to "mold" the bony regenerate to avoid the development of postdistraction malocclusion and to achieve the desired craniofacial form. Although the potential to mold the regenerate has important clinical implications, the safety and efficacy of such an acute manipulation of the bony regenerate form have not yet been investigated in the laboratory. The purpose of this study was to determine if the distraction regenerate could be molded and result in a bony union. Four adult female dogs underwent bilateral mandibular distraction with an external multiplanar device (Stryker, Osteonics). After a latency period of 5 days, the mandibles underwent linear (anteroposterior) and angular (superoinferior) distraction to produce an anterior open bite of approximately 30 degrees. At the conclusion of the distraction procedure, the distraction sites were molded to close the open bite. In two dogs, the maneuver was performed over 3 days by changing the angulation of the devices (gradual molding), and in the other two dogs, molding was achieved with a single movement (acute molding). In the latter, the distraction devices were adjusted and reapplied to allow for anatomical fixation during the consolidation period of 49 days. According to the research protocol, the mandibles were assessed serially by cephalograms and computed tomography (CT) scans. All dogs survived the study without complications. The bony regenerate was easily molded in both groups to close the surgically created open bite. After molding, all the regenerates showed CT scan evidence of solid bone (consolidation), which was classified as "extended" on the Hamanishi scale. After the dogs were killed and soft tissue was removed, the regenerate seemed to be robust on gross examination without any evidence of fibrous nonunion. In addition, histological study of the regenerate confirmed the bony union. The study demonstrates that the mandible can be successfully molded into a desired anatomical position immediately after distraction without producing a fibrous union. Furthermore, it has been demonstrated that the bony regenerate is sufficiently malleable before consolidation to undergo either acute or gradual angular molding without disturbing osteogenic potential. The ability to mold the regenerate without the fear of creating a fibrous union or destroying bony potential provides the surgeon the capability to optimize the dental occlusion and mandibular form as part of the distraction treatment process.     

Impurities in a morphine sulfate drug product identified as 5-(hydroxymethyl)-2-furfural, 10-hydroxymorphine and 10-oxomorphine

Stability testing of morphine sulfate formulated with nonpareil sugar seeds (consisting of sucrose and starch) and fumaric acid revealed the formation of the three impurities 5-(hydroxymethyl)-2-furfural, 10-hydroxymorphine and 10-oxomorphine. 5-(Hydroxymethyl)-2-furfural was isolated via semipreparative HPLC utilizing volatile mobile phase constituents and was identified by analysis of its HRMS and NMR spectra. 10-Hydroxymorphine and 10-oxomorphine were obtained via semipreparative HPLC and subsequent removal of ion-pair reagents using an anion exchange resin, or by solid phase extraction, and identified by spectroscopic analysis followed by comparison with authentic materials. 5-(Hydroxymethyl)-2-furfural is a degradation product of hexose sugars, and its formation in the presence of morphine sulfate formulated with fumaric acid suggests that caution should be exercised when including nonpareil seeds in formulations that contain acidic drug salts and/or acid excipients. The preliminary results of tests on the interaction of acidic salts of some other drugs with nonpareil seeds are presented.     

A 6-year study of cognition and spatial function in the demented and non-demented elderly: the Sydney Older Persons Study

BACKGROUND: Spatial function has been suggested to be disproportionately worse in people with dementia with Lewy bodies (DLB) than other dementia groups, and poor performance on the Mini-Mental State Examination pentagon copying (PC) task has been proposed as adequate for assessing this. We aimed to establish the prevalence of poor PC in the non-demented elderly; determine the validity of the use of PC as a spatial function test, and determine if poor PC is more common in DLB than non-DLB dementias. METHODS: In a population-based sample of 299 participants, 126 were rated as being cognitively normal (clinical rating scale [CDR] = 0), 95 mildly cognitively impaired (CDR = 0.5), and 78 met criteria for dementia, 19 of whom met criteria for probable DLB (pDLB) and 25 with none of the core features of DLB (non-DLB). The accuracy of PC performance was determined across CDR groups, and the relationship of PC to performance on a broad range of cognitive tests was evaluated. The dementia groups were compared cross-sectionally to determine differences in PC and other cognitive test performance, as well as 3 and 6 years earlier to determine cognitive differences at initial stages of cognitive decline. RESULTS: Poor PC was common in the non-demented elderly (39% CDR = 0; 43% CDR = 0.5). In this non-demented group, PC was selectively related to tests of spatial function. Poor PC was not significantly different in the pDLB and non-DLB groups at any assessment time, however it became more prevalent as dementia severity increased. Memory function and verbal fluency were more impaired in the pDLB group in the early stages of the disorder. COMMENT: PC appears to be a good measure of spatial function in the elderly. However, in contrast to other findings of poor spatial skills in DLB when dementia is in the mild to moderate stages, poor PC performance has not been shown to be a good early marker of DLB and its clinical correlates are yet to be determined.     

Serum ghrelin levels in response to glucose load in obese subjects post-gastric bypass surgery

OBJECTIVE: We sought to elucidate further the mechanisms leading to weight loss after gastric bypass (GBP) surgery in morbidly obese individuals. Ghrelin is a gastroenteric appetite-stimulating peptide hormone, fasting levels of which decrease with increasing adiposity and increase with diet-induced weight loss. In addition, ghrelin levels rapidly decline postprandially. RESEARCH METHODS AND PROCEDURES: We measured serum ghrelin responses to a 75-g oral glucose tolerance test (OGTT) in 6 subjects who had undergone GBP surgery 1.5 +/- 0.7 years before testing and compared these responses with 6 obese subjects about to undergo GBP surgery, 6 obese nonsurgical subjects (matched for BMI to the post-GBP surgical group), and 5 lean subjects. RESULTS: Despite weight loss induced by the GBP surgery, fasting serum ghrelin levels were significantly lower in the post-GBP surgery group than in the lean subject (by 57%) or pre-GBP surgery (by 45%) group. Serum ghrelin levels during the OGTT were significantly lower in postoperative than in lean, obese pre-GBP surgical, or obese nonsurgical subjects. The magnitude of the decline in serum ghrelin levels between 0 and 120 minutes post-OGTT was significantly smaller in postoperative (by 62%), obese pre-GBP surgical (by 80%), or obese nonsurgical (by 69%) subjects in comparison with lean subjects. DISCUSSION: Serum ghrelin levels in response to OGTT are lower in subjects post-GBP surgery than in either lean or obese subjects. Tonically low serum ghrelin levels may be involved in the mechanisms inducing sustained weight loss after GBP surgery.     

Single-follicular-unit hair transplantation to correct cleft lip moustache alopecia.

OBJECTIVE: To present the case of an 18-year-old boy with a cleft lip scar and an obligatory need for facial hair who underwent single-follicular-unit graft hair transplantation that resulted in significant moustache hair restoration in a single procedure. SETTING: The surgery was performed in an outpatient private practice setting using oral sedation and local anesthesia. RESULTS: Advances in instrumentation technology and an increased understanding of the anatomical clustering of hair follicles into so-called "follicular units" containing one to six hairs per unit has resulted in a rapid expansion of hair restoration surgery into new areas including female-pattern alopecia, scarring alopecias, and cosmetic surgery scars. These new techniques can be employed to create natural-looking hair lines in front of artificial hair replacement systems; to improve unnatural looking, old "large-plug" hair transplants; and to correct discontinuity of eyebrows and hairlines in patients with congenital facial clefts. Increased awareness is needed to incorporate follicular-unit graft hair transplant surgery into the family of corrective surgery subspecialties.